RFR: 8277861: Terminally deprecate Thread.stop

[Alan Bateman]

Thread.stop is inherently unsafe and has been deprecated since Java 1.2 (1998). It's time to terminally deprecate this method so it can be degraded and removed in the future.

This PR does not propose any changes to the JVM TI StopThread function (or the corresponding JDWP command or JDI method).

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Commit messages:
 - Initial commit

Changes: https://git.openjdk.java.net/jdk/pull/6616/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6616&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8277861
  Stats: 2 lines in 2 files changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6616.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6616/head:pull/6616

PR: https://git.openjdk.java.net/jdk/pull/6616